268311821 has 2 divisors, whose sum is σ = 268311822. Its totient is φ = 268311820.

The previous prime is 268311817. The next prime is 268311847. The reversal of 268311821 is 128113862.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 261986596 + 6325225 = 16186^2 + 2515^2 .

It is a cyclic number.

It is not a de Polignac number, because 268311821 - 2² = 268311817 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (268310821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 134155910 + 134155911.

It is an arithmetic number, because the mean of its divisors is an integer number (134155911).

Almost surely, 2^268311821 is an apocalyptic number.

It is an amenable number.

268311821 is a deficient number, since it is larger than the sum of its proper divisors (1).

268311821 is an equidigital number, since it uses as much as digits as its factorization.

268311821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4608, while the sum is 32.

The square root of 268311821 is about 16380.2265246852. The cubic root of 268311821 is about 644.9805262233.

The spelling of 268311821 in words is "two hundred sixty-eight million, three hundred eleven thousand, eight hundred twenty-one".